Senna armata
Encyclopedia
Senna armata is a species of flowering plant in the legume family
known by the common names spiny senna and desert senna. It is native to the desert regions around the intersection of Nevada
, Arizona
, eastern California
and northern Baja California
, where it grows in sandy and rocky habitat, such as arroyos
. It is a shrub
growing up to a meter tall, its grooved, branching stems often narrowing to thorns at their tips. The spiny branches are coated in tubular hairs which help protect it from hot desert air. The spine-tipped leaves are each made up of two to four pairs of small leaflets. The leaves are ephemeral, dropping soon after emerging, leaving the shrub naked most of the time. Flowers occur singly or in small clusters in leaf axils. They are fragrant and showy, with five petals in shades of yellow to salmon pink, each measuring roughly a centimeter long. The fruit is a legume pod up to 4 centimeters long.
Fabaceae
The Fabaceae or Leguminosae, commonly known as the legume, pea, or bean family, is a large and economically important family of flowering plants. The group is the third largest land plant family, behind only the Orchidaceae and Asteraceae, with 730 genera and over 19,400 species...
known by the common names spiny senna and desert senna. It is native to the desert regions around the intersection of Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, Arizona
Arizona
Arizona ; is a state located in the southwestern region of the United States. It is also part of the western United States and the mountain west. The capital and largest city is Phoenix...
, eastern California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
and northern Baja California
Baja California
Baja California officially Estado Libre y Soberano de Baja California is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is both the northernmost and westernmost state of Mexico. Before becoming a state in 1953, the area was known as the North...
, where it grows in sandy and rocky habitat, such as arroyos
Arroyo (creek)
An arroyo , a Spanish word translated as brook, and also called a wash is usually a dry creek or stream bed—gulch that temporarily or seasonally fills and flows after sufficient rain. Wadi is a similar term in Africa. In Spain, a rambla has a similar meaning to arroyo.-Types and processes:Arroyos...
. It is a shrub
Shrub
A shrub or bush is distinguished from a tree by its multiple stems and shorter height, usually under 5–6 m tall. A large number of plants may become either shrubs or trees, depending on the growing conditions they experience...
growing up to a meter tall, its grooved, branching stems often narrowing to thorns at their tips. The spiny branches are coated in tubular hairs which help protect it from hot desert air. The spine-tipped leaves are each made up of two to four pairs of small leaflets. The leaves are ephemeral, dropping soon after emerging, leaving the shrub naked most of the time. Flowers occur singly or in small clusters in leaf axils. They are fragrant and showy, with five petals in shades of yellow to salmon pink, each measuring roughly a centimeter long. The fruit is a legume pod up to 4 centimeters long.